Filter control program, filter control method, and filter control device

Abstract

To make it possible for an apparatus on a receiving side to timely receive a message depending on a situation.SOLUTION: A message concerning an event such as a traffic accident which is created by a transmitting vehicle 1 and traffic monitoring camera 4 is inputted to a distance filter 32. The distance filter 32 performs filtering based on a distance, and passes a message concerning an event occurring in a place within a predetermined distance from a receiving vehicle 4 serving as a reference. The message having passed through the distance filter 32 is registered in a buffer 31, and then read and sent to a receiving vehicle 2. When an available capacity of the buffer 31 falls below a first threshold, the distance filter 32 is controlled to contract a passable range.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a filter control program, a filter control method, and a filter control apparatus. [Background Art]

[0002] Several techniques are known for controlling a filter that extracts part of data from input data (see, for example, Patent Documents 1 to 4).

[0003] For example, a technique for selecting a packet signal to be processed from among packet signals received from another wireless device is known.

[0004] Further, for example, a technique is known in which a distribution destination terminal device is selected based on the content of a message received from a terminal device and the position information of each terminal device, and the message is distributed.

[0005] Further, for example, a technique is known for automatically filtering network messages in an aircraft aeronautical network based on the current system context.

[0006] Further, for example, a technique relating to a security device and a security system at an access level that uses a security rule filter generated in response to an analysis result obtained by a statistical method on a header of packet data input through a switch fabric is known. [Prior Art Documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. WO 2014 / 002485 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2013-150245 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2017-216673 [Patent Document 4] Special Publication No. 2011-523822 [Overview of the project] [Problems that the invention aims to solve]

[0008] One of the services enabled by connected cars and smart cities is the provision of messages such as traffic information. For this service, instead of the provider directly sending the message to the recipient, a known method is used in which the transmitting device sends the message to a relay device, and the receiving device receives the message from the relay device. For example, a message from the transmitting device can be sent to the receiving device via a distributed messaging system such as Apache Kafka (registered trademark) configured on the relay device. In this method of providing messages via a relay device, the transmitting device only needs to specify the relay device as the destination of the message, and does not need information to identify the receiving device.

[0009] In this method, the relay device temporarily stores messages received from the transmitting device in a buffer, and then reads the messages from the buffer and sends them to the receiving device in response to a transmission request from the receiving device. Since the buffer holds messages in a queue, older messages are deleted from the buffer. Therefore, this method is suitable for handling messages that are updated moment by moment, such as traffic information. In addition, with this method, the receiving device only needs to request the relay device to transmit the desired message when it is able to receive the message, so it can receive messages that are relevant to the situation in a timely manner.

[0010] However, in connected cars and smart cities, there are numerous transmitting devices that provide messages, such as vehicles traveling on the road and surveillance cameras installed along the road. When a relay device receives a large number of messages from such devices, it may not be able to store all of the received messages in its buffer, and some messages may overflow the buffer. In this case, the receiving device may not be able to receive messages appropriate to the situation in a timely manner. In addition, in distributed messaging systems, received messages may be processed sequentially without being discarded, which may cause delays before the receiving device receives the message.

[0011] In one aspect, the present invention aims to enable a receiving device to receive situation-appropriate messages in a timely manner. [Means for solving the problem]

[0012] One approach involves a filter control program that instructs the computer to perform the following steps: This process sets a transparency range for a filter that filters input data based on distance, with the location of the receiving device that provides the data as the reference position. Then, if the free capacity of the buffer where the filtered data is registered falls below a first threshold, the set transparency range is reduced. [Effects of the Invention]

[0013] One aspect of this is that the receiving device will be able to receive situation-appropriate messages in a timely manner. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram illustrates the first example of a message delivery system. [Figure 2] This diagram illustrates a second example of a message delivery system. [Figure 3] This diagram illustrates the sudden increase in message volume. [Figure 4]It is a diagram explaining the control of a range filter. [Figure 5] It is a diagram showing an example of a functional configuration of a relay device. [Figure 6] It is a diagram (Part 1) explaining a specific example of control of a range filter. [Figure 7] It is a diagram (Part 2) explaining a specific example of control of a range filter. [Figure 8] It is a diagram (Part 3) explaining a specific example of control of a range filter. [Figure 9] It is a diagram (Part 4) explaining a specific example of control of a range filter. [Figure 10] It is a diagram (Part 5) explaining a specific example of control of a range filter. [Figure 11] It is a diagram showing an example of a hardware configuration of a computer. [Figure 12] It is a flowchart showing the processing content of range filter control processing. MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, embodiments will be described in detail with reference to the drawings.

[0016] In connected cars and smart cities, various services that utilize a large amount of video data acquired by various imaging devices such as in-vehicle cameras mounted on vehicles and surveillance cameras installed on roads have been proposed. One such service, a service that provides messages such as traffic information, will be described.

[0017] FIG. 1 shows a first example of a message providing system.

[0018] The system shown in FIG. 1 is used for a service that provides, as a message, traffic information corresponding to an event encountered by a transmitting vehicle 1, which is a message provider, to a receiving vehicle 2, which is a message recipient that receives the message.

[0019] The system shown in Figure 1 comprises a transmitting vehicle 1, a receiving vehicle 2, and a relay device 3. All of these components are connected to a communication network (not shown), and various types of data can be exchanged between the transmitting vehicle 1 and the relay device 3, and between the receiving vehicle 2 and the relay device 3.

[0020] The transmitting vehicle 1 is equipped with a camera 11 and an analysis device 12.

[0021] The camera 11 captures images of the surroundings of the transmitting vehicle 1 on which it is mounted, and outputs video data representing those images.

[0022] The analysis device 12 analyzes the video data output from the camera 11 to determine the event encountered by the transmitting vehicle 1 (for example, a traffic accident scene or tire slip due to road freezing or wetness). This analysis uses, for example, the results of machine learning that uses the relationship between previously obtained video data and the road conditions at the time the video data was obtained. The analysis device 12 creates data representing a message corresponding to this analysis result and sends it to the relay device 3. In creating this message, for example, if the analysis result is a traffic accident scene, a message notifying of a road closure due to the traffic accident is created, and if the analysis result is tire slip, a message warning of slipping is created.

[0023] Furthermore, the analysis device 12 includes in the message it sends to the relay device 3 the location information of the transmitting vehicle 1 when it captured the video that triggered the creation of the message, as location information of the event determined as a result of the video analysis.

[0024] For example, if the message is a notification of a road closure due to a traffic accident, the analysis device 12 will include the location information of the transmitting vehicle 1 at the time the video of the traffic accident was captured in the message. Also, for example, if the message is a warning about slipping caused by a tire slip, the analysis device 12 will include the location information of the transmitting vehicle 1 at the time the video showing the occurrence of the tire slip was captured in the message.

[0025] The location information of the transmitting vehicle 1 is acquired, for example, by a location detection device (for example, a GPS (Global Positioning System) device) mounted on the transmitting vehicle 1 that continuously detects the location of the transmitting vehicle 1 on Earth.

[0026] The relay device 3 has a buffer 31. When the relay device 3 receives a message transmitted from the transmitting vehicle 1, it registers and stores the message in the buffer 31, which is a data memory. In the aforementioned Apache Kafka (registered trademark), the buffer 31 corresponds to a partition.

[0027] When receiving vehicle 2 needs traffic information, it sends a message transmission request to relay device 3. Upon receiving this transmission request, relay device 3 reads the message from buffer 31 and transmits it to receiving vehicle 2. By receiving this message, receiving vehicle 2 obtains the traffic information represented in the message.

[0028] In the service shown in Figure 1, messages are provided from the transmitting vehicle 1 (the provider) to the receiving vehicle 2 (the recipient) in the manner described above.

[0029] In the system shown in Figure 1, the buffer 31 provided by the relay device 3 holds messages in a queue, and older messages are deleted from the buffer 31. Therefore, this system is suitable for handling messages whose content is constantly updated over time, such as traffic information. Furthermore, in this system, the receiving vehicle 2 only needs to request the transmission of the desired message depending on the situation when it is possible to receive a message, thus enabling timely reception of situation-appropriate messages.

[0030] However, in connected cars and smart cities, there can be many transmitting vehicles 1 that provide messages. Also, for example, numerous surveillance cameras installed on roads can also be message providers. When the relay device 3 receives many messages from such devices, it may not be possible to register all messages in the buffer 31, and some messages may overflow from the buffer 31 and be lost. If some messages are lost, the receiving vehicle 2 may not be able to receive messages appropriate to the situation in a timely manner. Furthermore, in the case of Apache Kafka (registered trademark) mentioned above, although data is not lost, the result may be that the messages received by the receiving vehicle are not the most up-to-date.

[0031] Therefore, the relay device 3 registers and stores in the buffer 31 only those messages transmitted from the transmitting vehicle 1 in which the location of the event that triggered the creation of the message is within a predetermined distance from the receiving vehicle 2. Next, this method will be explained.

[0032] Figure 2 shows a second example of a message delivery system.

[0033] The system shown in Figure 2 is the same as the system shown in Figure 1, but with the addition of a distance filter 32. For illustrative purposes, a traffic surveillance camera 4 is also shown in Figure 2.

[0034] The traffic surveillance camera 4 is a device installed on the road and includes a camera 11 and an analysis device 12 that have the same functions as those mounted on the transmitting vehicle 1. However, the camera 11 and analysis device 12 are not shown in Figure 2. The location information of the installation location of the traffic surveillance camera 4 may be pre-set in the analysis device 12, and the messages created by the analysis device 12 may include this location information as information about the location where the event that triggered the creation of the message occurred.

[0035] In the following explanation, the transmitting vehicle 1 and the traffic surveillance camera 4 will be collectively referred to as the "provider equipment." Similarly, the receiving vehicle 2 will be referred to as the "receiving equipment" in the following explanation, corresponding to the provider equipment.

[0036] In the system shown in Figure 2, the receiving vehicle 2 transmits its location information to the relay device 3 as it occurs. This location information can be obtained, for example, by installing the aforementioned location detection device on the receiving vehicle 2 and using that location detection device.

[0037] The distance filter 32 is provided in the relay device 3. The relay device 3 receives messages transmitted from the provider device and inputs them to the distance filter 32. The distance filter 32 is a filter that performs distance-based filtering on the input messages. More specifically, the distance filter 32 transmits and outputs messages from the input messages in which the location of the event that triggered the creation of the message occurred is within a predetermined distance from the location of the receiving device. For example, the distance filter 32 transmits messages from the input messages that concern events that occurred at locations within a 10km x 10km rectangular area centered on the location of the receiving vehicle 2. For example, if the location information is represented by longitude and latitude, in this case, the distance filter 32 transmits messages that concern events that occurred at locations within a range of longitude and latitude differences equivalent to 5km in the east-west and north-south directions, respectively, centered on the location of the receiving vehicle 2.

[0038] The relay device 3 registers and stores in the buffer 31 messages that have passed through the distance filter 32 and been output from the analysis device 12 of the providing device.

[0039] Other operations in the system shown in Figure 2 are the same as those in the system shown in Figure 1.

[0040] In the system shown in Figure 2, the inclusion of such a distance filter 32 allows the receiving device to receive messages created in response to events occurring at locations within a predetermined distance from the receiving vehicle 2. Such messages are presumed to be beneficial to the receiving device. Therefore, this system enables the receiving device to receive situation-appropriate messages in a timely manner.

[0041] However, there are cases where the amount of messages transmitted from a provider device located within a predetermined distance from the receiving device to the relay device 3 increases sharply. An example of this case will be explained using Figure 3.

[0042] In Figure 3, [A] and [B] on the left illustrate the processing performed by the relay device 3 upon receiving a message transmitted from the transmitting vehicle 1. Note that, in this case, the number of messages that can be registered in the buffer 31 is assumed to be 5.

[0043] Furthermore, in Figure 3, the map on the right shows seven transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7) and one receiving vehicle 2. The map also schematically shows the range of locations where events that trigger the creation of messages transmitted by the distance filter 32 occur, indicated by dashed lines. As can be seen by referring to this map, the locations where events that trigger the creation of messages transmitted by the seven transmitting vehicles 1 occur are all within this range.

[0044] First, we assume a scenario where messages are sent from each of the five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5), while no messages are sent from the remaining two transmitting vehicles 1 (1-6, 1-7). In this scenario, it is assumed that three transmitting vehicles 1 (1-1, 1-2, 1-3) created and sent messages warning of slippage because their tires slipped while driving. Also, in this scenario, it is assumed that two transmitting vehicles 1 (1-4, 1-5) encountered a traffic accident scene and created and sent messages notifying drivers of a road closure.

[0045] [A] shows the situation where the relay device 3 receives messages transmitted from each of the five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5) on the map on the right. In this case, the distance filter 32 allows a total of five messages transmitted from each of the five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5) to pass through. Since the buffer 31 can hold five messages, the relay device 3 can register and hold all five messages that the distance filter 32 has allowed through in the buffer 31, and then transmit those five messages to the receiving vehicle 2. Therefore, in this case, the receiving vehicle 2 can receive messages appropriate to the situation in a timely manner.

[0046] Next, we assume that messages are sent from the remaining two transmitting vehicles 1 (1-6, 1-7), resulting in a situation where messages are sent from each of the seven transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7). In this scenario, it is assumed that the remaining two transmitting vehicles 1 (1-6, 1-7) have encountered a new traffic accident and have created and sent a message notifying that a new road closure has occurred.

[0047] [B] represents a situation where the number of messages received by the relay device 3 increases sharply from the case in [A], more specifically, when messages are received from each of the seven transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7) shown on the map on the right. In this case, the distance filter 32 allows a total of seven messages transmitted from each of the seven transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7) to pass through. However, since the buffer 31 can only register up to five messages, the relay device 3 cannot register all seven messages that the distance filter 32 has allowed to pass through in the buffer 31, and some messages are lost. Therefore, even if all messages held in the buffer 31 are sent to the receiving vehicle 2, in this case, the receiving vehicle 2 may not be able to receive the appropriate message in a timely manner.

[0048] Thus, if an excessive amount of messages is transmitted, exceeding the amount that the relay device 3 can register in the buffer 31, it becomes impossible to deliver situation-appropriate messages to the receiving vehicle 2 in a timely manner. Therefore, in order to avoid a situation where messages cannot be registered in the buffer 31, the distance filter 32 is controlled as illustrated in Figure 4.

[0049] This control involves changing the setting of the distance between the receiving device and the location of the event that triggers the creation of a message on the providing device, which is the setting of the range over which the distance filter 32 allows messages to pass through. This control is performed when the free capacity of the buffer 31, i.e., the number of messages that can be registered in the buffer 31, falls below a predetermined threshold and it is determined that there is no more free space in the buffer 31.

[0050] An embodiment for controlling such a distance filter 32 will be described.

[0051] First, let's explain Figure 5. Figure 5 shows an example of the functional configuration of the relay device 3. This relay device 3 is an example of a filter control device that performs the control described above.

[0052] This relay device 3 comprises the following components: a buffer 31, a distance filter 32, a receiving unit 33, a transmitting unit 34, a monitoring unit 35, and a control unit 36.

[0053] Buffer 31 is a data memory that registers and stores messages transmitted from the transmitting vehicle 1, traffic surveillance camera 4, and other provider-side devices.

[0054] The distance filter 32 is a filter that filters the input data based on distance. More specifically, the distance filter 32 allows the input message to pass through if the location of the event that triggered the creation of the message is within a predetermined distance from the receiving vehicle 2, which is the receiving device.

[0055] The receiving unit 33 receives various types of information, such as messages, transmitted from the transmitting vehicle 1 and traffic surveillance camera 4, as well as various types of information transmitted from the receiving vehicle 2.

[0056] In this embodiment, before sending the created message, the provider device sends the number of messages (usually one) and location information of the event that triggered the creation of the message to the relay device 3 as preliminary information. The receiving unit 33 receives the message transmitted from the provider device and also receives the preliminary information.

[0057] Furthermore, in this embodiment, the receiving unit 33 also receives message transmission requests transmitted from the receiving device and location information of the receiving device that is transmitted from the receiving device to the relay device 3 from time to time.

[0058] The transmitting unit 34 transmits various types of information to the receiving device. For example, when the receiving unit 33 receives a message transmission request transmitted from the receiving device, the transmitting unit 34 reads the message from the buffer 31 and transmits the message to the receiving device.

[0059] Furthermore, the transmitting unit 34 also transmits various types of information addressed to the providing device. For example, upon receiving preliminary information by the receiving unit 33, the transmitting unit 34 sends a message transmission request related to the preliminary information to the providing device, which is the source of the preliminary information, and the providing device transmits the message upon receiving the transmission request.

[0060] The monitoring unit 35 monitors the receiving unit 33 and obtains location information of the location where the aforementioned event related to the content of the message created by the providing device, as indicated in the preliminary information transmitted from the providing device, and location information of the receiving device transmitted from the receiving device. The monitoring unit 35 also monitors the buffer 31 and obtains the number of messages that can be registered in the buffer 31.

[0061] The control unit 36 ​​sets a transmission range for the distance filter 32 and controls the transmission range using information obtained from monitoring by the monitoring unit 35.

[0062] In this control, the control unit 36 ​​first determines the number of messages that will pass through the distance filter 32 based on the location information obtained from the providing device and the receiving device, and the predetermined distance value used by the distance filter 32 as a condition for message transmission. The control unit 36 ​​also calculates the available capacity of the buffer 31 where data that has passed through the distance filter 32 is registered, based on the determined number of messages and the number of data that can be registered in the buffer 31. The control unit 36 ​​compares this available capacity with a first threshold, and if the available capacity falls below the first threshold, it performs control to reduce the transmission range of the distance filter 32 by shortening the predetermined distance.

[0063] Furthermore, if the available capacity of the buffer 31 exceeds the second threshold after the transmission range of the distance filter 32 has been reduced, the control unit 36 ​​further controls the distance filter 32 to expand the transmission range of the reduced distance filter 32. The second threshold is set to a value equal to or greater than the first threshold.

[0064] A specific example of the control of the distance filter 32 in the relay device 3, which is equipped with the above-mentioned components, will be further explained with reference to Figures 6 to 10.

[0065] The left side of each of Figures 6 to 10 illustrates the processing performed by the relay device 3 upon receiving a message transmitted by the transmitting vehicle 1. Here, the number of messages that can be registered in the buffer 31 is set to 10, and the first and second thresholds mentioned above are set to 3 and 6, respectively.

[0066] In Figure 6, the map on the right shows five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5) and one receiving vehicle 2. The map also schematically represents the range of events that trigger the creation of messages transmitted by the distance filter 32, indicated by dashed rectangles. For the purposes of this explanation, the area enclosed by these dashed rectangles is assumed to be a 10km x 10km radius centered on the location of receiving vehicle 2. As can be seen from this map, the locations of the events that trigger the creation of messages transmitted by the five transmitting vehicles 1 are all within this range.

[0067] Figure 6 illustrates the case where messages are sent from each of the five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5). More specifically, in three of these transmitting vehicles 1 (1-1, 1-2, 1-3), a message warning of slippage was created and sent because tire slippage occurred while driving. In addition, in two of these transmitting vehicles 1 (1-4, 1-5), a message notifying of a road closure was created and sent because a traffic accident occurred.

[0068] In the case of Figure 6, the distance filter 32 will allow a total of five messages transmitted from each of the five transmitting vehicles 1 (1-1, 1-2, 1-3, 1-4, 1-5) to pass through. Since the buffer 31 can hold 10 messages, the relay device 3 can register and store all five messages that the distance filter 32 has passed through in the buffer 31, and then transmit those five messages to the receiving vehicle 2. Therefore, in this case, by registering and storing the five messages in the buffer 31, the receiving vehicle 2 can receive messages appropriate to the situation in a timely manner.

[0069] Next, let's explain the case of Figure 7. Figure 7 shows that after the case of Figure 6, a new traffic accident occurs within the range of the location where the event that triggers the creation of a message to be transmitted by the distance filter 32 occurred. In Figure 7, three transmitting vehicles 1 (1-6, 1-7, 1-8) encounter the scene of this new traffic accident, and these three transmitting vehicles 1 (1-6, 1-7, 1-8) create and transmit a message notifying that a road closure has occurred.

[0070] In the case of Figure 7, the distance filter 32 will allow a total of 8 messages transmitted from each of the 8 transmitting vehicles 1 (1-1 to 1-8) to pass through. Although the buffer 31 can hold 10 messages, if these 8 messages are registered in the buffer 31, the number of messages that can be registered in the buffer 31 becomes 10-8=2, which falls below the first threshold, and it is determined that there is no remaining space in the buffer 31.

[0071] Therefore, the control unit 36 ​​controls the distance filter 32 in this case to reduce the range of locations where events that trigger the creation of messages transmitted by the distance filter 32 occur, as illustrated in Figure 8, to the range enclosed by the solid rectangle. Here, let's assume that this range enclosed by the solid rectangle is a 5km x 5km area centered on the position of the receiving vehicle 2.

[0072] As can be seen by referring to the map shown in Figure 8, three of the eight transmitting vehicles 1 (1-1 to 1-8), specifically transmission vehicles 1 (1-1, 1-2, and 1-3), are outside the area enclosed by the solid rectangle. Therefore, the distance filter 32 will allow a total of five messages transmitted from the remaining five transmitting vehicles 1 (1-4 to 1-8) to pass through. At this time, the relay device 3 registers and stores all five messages that the distance filter 32 has passed through in the buffer 31, which has sufficient free capacity, and then can transmit these five messages to the receiving vehicle 2. Therefore, in this case, by registering and storing these five messages in the buffer 31, the receiving vehicle 2 can receive messages appropriate to the situation in a timely manner.

[0073] After the control described in Figure 8, if the number of messages that can be registered in buffer 31 exceeds the second threshold and it is determined that there is sufficient free space in buffer 31, the control unit 36 ​​further controls the distance filter 32 to expand the transmission range of the distance filter 32. This control will be explained using Figures 9 and 10.

[0074] Figure 9 shows the case where, after the control described in Figure 8, the two transmitting vehicles 1 (1-4, 1-5) have stopped creating and transmitting messages after the traffic accident they encountered at the scene has been resolved and the road closure has been lifted.

[0075] In the case of Figure 9, the distance filter 32, which reduces the transmission range, will allow a total of three messages transmitted from the remaining three transmission vehicles 1 (1-6, 1-7, and 1-8) out of the five transmission vehicles 1 (1-4 to 1-8) to pass through. Since buffer 31 can hold 10 messages, even if these three messages are registered in buffer 31, the number of messages that can be registered in buffer 31 is 10-3=7, which exceeds the second threshold, and it is determined that there is sufficient space in buffer 31.

[0076] In this case, the control unit 36 ​​further controls the distance filter 32 to expand the range of the location of the event that triggers the creation of a message transmitted by the distance filter 32, as illustrated in Figure 10. The map shown in Figure 10 shows the case where, as a result of this control, the range of the location of the event that triggers the creation of a message transmitted by the distance filter 32 returns to the range before the reduction in the range of the location (represented by the dashed rectangle).

[0077] The control of the distance filter 32 by the control unit 36 ​​is performed as described above.

[0078] Furthermore, the monitoring unit 35 and the control unit 36 ​​in the relay device 3 shown in Figure 5 may be configured using a combination of a computer and software.

[0079] Figure 11 shows an example of a computer hardware configuration.

[0080] The computer 40 shown in Figure 11 comprises, for example, a processor 41, memory 42, storage device 43, reader 44, communication interface 46, and input / output interface 47. These components are connected via a bus 48, allowing for the exchange of data between them.

[0081] The processor 41 may be a single processor, a multi-processor, or a multi-core processor. The processor 41 uses the memory 42 to execute a distance filter control program that describes the procedure for the distance filter control processing described later, thereby providing the functions of each component of the relay device 3 in Figure 5.

[0082] The memory 42 is, for example, a semiconductor memory and may include a RAM area and a ROM area.

[0083] The storage device 43 is, for example, a semiconductor memory such as a hard disk or flash memory, or an external storage device. RAM is an abbreviation for Random Access Memory, and ROM is an abbreviation for Read Only Memory.

[0084] The reader 44 accesses the removable storage medium 45 according to instructions from the processor 41. The removable storage medium 45 can be implemented as, for example, a semiconductor device (such as a USB memory stick), a medium in which information is input / output by magnetic action (such as a magnetic disk), or a medium in which information is input / output by optical action (such as a CD-ROM or DVD). Note that USB is an abbreviation for Universal Serial Bus. CD is an abbreviation for Compact Disc. DVD is an abbreviation for Digital Versatile Disk.

[0085] The communication interface 46 transmits and receives data via a communication network (not shown) according to instructions from, for example, the processor 41.

[0086] The input / output interface 47 is connected to the receiving unit 33 and acquires various data sent from the receiving unit 33. For example, the input / output interface 47 acquires messages and background information transmitted from the providing device, and location information of the receiving device transmitted from the receiving device, from the receiving unit 33.

[0087] The program executed by the processor 41 of this computer 40 is provided, for example, in the following form. (1) It is pre-installed on the storage device 43. (2) Provided by a removable storage medium 45. (3) Provided from a server such as a program server to the communication interface 46 via a communication network.

[0088] The hardware configuration of computer 40 is illustrative, and the embodiments are not limited thereto. For example, some or all of the functions of the above-mentioned functional units may be implemented as hardware such as FPGAs and SoCs. FPGA stands for Field Programmable Gate Array, and SoC stands for System-on-a-chip.

[0089] Next, the control process of the distance filter 32 performed in the relay device 3 shown in Figure 5 will be explained. Figure 12 is a flowchart showing the processing details of the distance filter control process.

[0090] Furthermore, if the monitoring unit 35 and control unit 36 ​​in Figure 5 are configured using a combination of the computer 40 and software shown in Figure 11, the processor 41 will be instructed to execute a control program that instructs the processor 41 to perform this distance filter control processing.

[0091] In the flowchart of Figure 12, the process of S101 is performed by the monitoring unit 35 in the relay device 3 of Figure 5. Furthermore, each of the processes from S102 to S110 is performed by the control unit 36 ​​in the relay device 3 of Figure 5.

[0092] Prior to this process starting, the control unit 36 ​​will perform an initial setting of the transmission range for the distance filter 32. As mentioned above, the distance filter 32 transmits and outputs messages where the location of the event that triggered the creation of the message is within a predetermined distance from the receiving device's position; therefore, the setting of this predetermined distance is performed as the initial setting of the transmission range.

[0093] When the flowchart in Figure 12 starts processing, first, in S101, the process of acquiring various types of data is performed.

[0094] This S101 process acquires preliminary information transmitted from each providing device, including the number of messages created by the providing device and the location information of the event that triggered the creation of those messages. This S101 process also acquires the location information of the receiving device, which is transmitted from the receiving device as needed. Furthermore, this S101 process also acquires information on the number of messages that can be registered in buffer 31 (the actual free capacity of buffer 31 at the time of this process). This acquired information is temporarily stored.

[0095] Next, in S102, a process is performed to determine whether there has been a change in at least one of the following: the number of messages created by the providing device and the number of messages that can be registered in the buffer 31, based on the data obtained by the processing in S101.

[0096] In this determination process, if it is determined that there has been a change in at least one of the parameters (the determination result is YES), the process proceeds to S103. On the other hand, if it is determined that there has been no change in either parameter (the determination result is NO), it is determined that there is no need to change the transparency range setting for the distance filter 32, and the process returns to S101, where the process of acquiring various data is performed again.

[0097] Note that if the S102 process is executed for the first time after the start of the control process in Figure 12, the S101 data acquisition process has only been executed once. Therefore, in this case, it is not possible to determine whether there has been a change in the number of messages created by the providing device and the number of messages that can be registered in the buffer 31. In this case, the S101 data acquisition process is performed a second time, and then the S102 determination process is performed.

[0098] In S103, the process of calculating the free space in buffer 31 is performed. This explanation will describe how this free space is calculated.

[0099] First, a process is performed to identify the range of the location where the event triggered by the message transmitted by the distance filter 32 occurs, based on the location information obtained from the receiving device and the predetermined distance value currently set in the distance filter 32. For example, if "10km" is set as the predetermined distance in the distance filter 32, this process identifies the range of existence as a rectangular area of ​​10km on each side centered on the location of the receiving device.

[0100] Next, a process is performed to obtain the number of messages that will pass through the distance filter 32. In this process, it is first determined whether the location of the event that triggered the creation of the message created by the provider device, which is represented by location information obtained from the preliminary information transmitted from the provider device, is included in the range. Then, the number of messages that are determined to be included in this determination is counted. For example, in the situation shown in Figure 6, the count of messages is 5, and in the situation shown in Figure 7, the count of messages is 8.

[0101] Next, a process is performed to calculate the remaining free space in the buffer 31 when a message that will pass through the distance filter 32 is registered. This free space is calculated by subtracting the number of messages that will pass through the distance filter 32 from the number of messages that can be registered in the buffer 31, which is obtained by the process in S101. For example, if the number of messages that can be registered in the buffer 31, which is obtained by the process in S101, is 10, then the free space in the buffer 31 will be 5 in the situation shown in Figure 6 and 2 in the situation shown in Figure 7.

[0102] In the S103 process, the free space of buffer 31 is calculated as described above.

[0103] Next, in S104, a process is performed to determine whether the change determined to exist by the process in S102 is an increase in the number of messages created by the provider device or a decrease in the number of messages that can be registered in buffer 31. If the result of this determination process is YES, that is, if the change determined to exist by the process in S102 is an increase in the number of messages created by the provider device or a decrease in the number of messages that can be registered in buffer 31, the process proceeds to S105.

[0104] If the result of the judgment process in S104 is YES, it means that the free capacity of buffer 31 is decreasing. In S105, a process is performed to determine whether the free capacity of buffer 31 falls below the first threshold and whether there is no more capacity left.

[0105] In the determination process of S105, if it is determined that the free capacity of buffer 31 falls below the first threshold (when the determination result is YES), the process proceeds to S106. Then, in S106, a process is performed to reduce the transmission range of the distance filter 32. As mentioned above, the distance filter 32 transmits messages whose location is within a predetermined distance from the receiving device, where the event that triggered the creation of the message occurred. Therefore, in the process of S106, a process is performed to shorten this predetermined distance. The amount of shortening in this predetermined distance is predetermined, for example, "1 km".

[0106] Next, in S107, a process is performed to change the transparency range of the distance filter 32 so that the predetermined distance setting is reflected in the distance filter 32. If the process in S107 is performed following the process in S106, a process is performed to reduce the transparency range of the distance filter 32 by reflecting the predetermined distance setting after the shortening by the process in S106 in the distance filter 32. After that, the process returns to S101, and the processes from S101 onwards are performed again.

[0107] On the other hand, in the determination process of S105, if it is determined that the free capacity of buffer 31 does not fall below the first threshold (when the determination result is NO), it is determined that there is no need to change the transparency range of the distance filter 32, and the process returns to S101, and the processes from S101 onwards are performed again.

[0108] By the way, if the result of the judgment process in S104 is NO, that is, if the change determined to be present in the process of S102 is a decrease in the number of messages created by the provider device or an increase in the number of messages that can be registered in buffer 31, the process proceeds to S108. If the result of the judgment process in S104 is NO, it means that the free capacity of buffer 31 is increasing. In S108, a process is performed to determine whether the free capacity of buffer 31 exceeds the second threshold and leaves sufficient margin.

[0109] In the determination process in S108, if it is determined that the free capacity of buffer 31 does not exceed the second threshold (when the determination result is NO), the process proceeds to S109. Then, in S109, in order to increase the free capacity of buffer 31, processing is performed to expand the transparency range of the distance filter 32. As mentioned above, the distance filter 32 transmits messages whose location is within a predetermined distance from the receiving device, where the event that triggered the creation of the message occurred. Therefore, in the processing of S109, processing is performed to extend this predetermined distance. The amount of extension in this predetermined distance is predetermined, for example, "1 km".

[0110] Next, in S110, a process is performed to calculate the available capacity of buffer 31. The method for calculating this available capacity is the same as the method used in S103, but the value of the predetermined distance set in distance filter 32 is the value after the extension performed in S109. After that, the process returns to S108, where a process is performed again to determine whether or not there is sufficient available capacity remaining in buffer 31.

[0111] In the determination process of S108, if it is determined that the free capacity of buffer 31 exceeds the second threshold and there is sufficient margin remaining (when the determination result is YES), the process proceeds to S107. Then, in S107, a process is performed to change the transparency range of the distance filter 32 so that the predetermined distance setting is reflected in the distance filter 32. If the process of S107 is performed immediately after the process of S108, a process is performed to expand the transparency range of the distance filter 32 by reflecting the predetermined distance setting after the extension performed in the most recent process of S109 in the distance filter 32. After that, the process returns to S101, and the processes from S101 onwards are performed again.

[0112] The process described above constitutes the distance filter control process. This process controls the distance filter 32, enabling the receiving device to receive messages appropriate to the situation in a timely manner.

[0113] As described above, embodiments of the disclosure and their advantages have been explained in detail, but those skilled in the art will be able to make various modifications, additions, and omissions without departing from the scope of the invention as clearly stated in the claims.

[0114] For example, the distance filter 32 may allow a message to pass through if the location of the event that triggered the creation of the input message is within a predetermined distance from the receiving device. In this case, the control unit 36 ​​can change the transmission range of the distance filter 32 by changing the predetermined distance. [Explanation of Symbols]

[0115] 1 Transmitting vehicle 2 Receiving vehicles 3. Relay device 4. Traffic surveillance cameras 11 Cameras 12 Analysis device 31 buffers 32 Distance Filters 33 Receiving unit 34 Transmitter 35 Monitoring Department 36 Control Unit 40 Computers 41 processors 42 memory 43 Storage device 44. Reader 45 Removable storage media 46 Communication Interfaces 47 Input / Output Interfaces 48 bus

Claims

1. A filter is used to filter input data based on distance, with the location of the receiving device that provides the data as the reference position. A transparency range is set for this filter. If the free space in the buffer where the data that has passed through the filter is registered falls below a first threshold, the set transparency range is reduced. A filter control program characterized by having a computer perform the processing.

2. The filter control program according to claim 1, characterized in that the transparency range is based on position information obtained from the providing device that provides the input data and the receiving device that receives the data read from the buffer.

3. The location information obtained from the providing device is information indicating the location of the event where the event related to the content of the message contained in the input data occurred. The position information obtained from the receiving device is information indicating the position of the receiving device. The filter allows the input data to pass through when the location where the event occurs is within a predetermined distance from the location of the receiving device. The filter control program according to claim 2.

4. The number of data points in the input data that will pass through the filter is determined based on the position information obtained from the providing device and the receiving device, respectively, and the value of the predetermined distance. The available capacity is calculated from the number of data items requested and the number of data items that can be registered in the buffer. If the available capacity falls below the first threshold, the predetermined distance is shortened. The filter control program according to claim 3, characterized in that the computer performs further processing.

5. If the available capacity exceeds a second threshold after the reduction of the transparent range, the reduced transparent range is expanded. A filter control program according to any one of claims 1 to 4, characterized in that the computer performs further processing.

6. A filter that performs distance-based filtering on input data has a transparency range set. If the free space in the buffer where the data that has passed through the filter is registered falls below a first threshold, control is performed to reduce the set transparency range. A filter control method characterized by the processing being performed by a computer.

7. A filter control device is characterized by having a filter that performs filtering on input data based on a distance with the position of the receiving device that receives the data as the reference position, and a control unit that performs control to reduce the set transparency range when the free capacity of the buffer where the data that has passed through the filter is registered falls below a first threshold.

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